Former CWD management zone population

Monitoring changes in deer populations in the former chronic wasting disease management zone (CWD-MZ) is important for understanding changes in CWD transmission and prevalence rates and the effectiveness of management efforts. Trends in the size of the deer population in the CWD-MZ are being monitoring using a combination of helicopter and fixed-wing aircraft surveys and population modeling.

Fixed-wing survey methods

Surveys consist of transects oriented east-west that extend across the length of DMUs.

There are three people in the helicopter: the pilot and two observers.

Transects are flown when there is at least 4-6 inches of snow cover.

Depending on wind conditions, transects are either flown north and south or east and west.

Enough transects flown in each section to be able to see all areas of the section.

Fly around 100ft above tree tops at 30-35 mph.

The location and number of deer are recorded on aerial photos.

Care is taken to prevent double counting of running deer.

Deer population trends

Current analyses that incorporate data from helicopter and fixed-wing surveys with historic harvest data suggest that the deer population in the CWD-MZ increased substantially during the 1990s, peaked at over 200,000 in 2002, and has been slowly declining since then.